Composite boat

ABSTRACT

A COMPOSITE BOAT COMPRISING A RIGID HULL HAVING AN INFLATABLE GUNWALE ATTACHED TO THE RIM OF THE HULL IN SUCH A MANNER THAT OVER A MAJOR PORTION OF THE LENGTH OF THE GUNWALE A PORTION OF THE GUNWALE PROJECTS OUTBOARD OF THE RIM OF THE HULL AND AT LEAST THE GREATER PART OF THE GUNWALE VOLUME LIES ABOVE THE RIM OF THE HULL. THE INFLATABLE GUNWALE IS PREFERABLY CONSTRUCTED WITH FLEXIBLE AIR CHAMBERS CONTAINED WITHIN AN OUTER SHAPE INDUCING PROTECTIVE COVERING OF RUBBERISED FABRIC.

D. W. SEAR ET AL Oct. 12, 1971 COMPOSITE BOAT 6 Sheets-Sheet 1 Filed Sept. 15, 1969 Oct. 12, 1971 D. w. SEAR ETAL 3,611,459

COMPOSITE BOAT 6 Sheets-Sheet 2 Filed Sept. 15, 1969 Oct. 12, 1971 D. w. SEAR EIAL 3,611,459

COMPOSITE BOAT Filed Sept. 15, 1969 6 Sheets-Sheet 5 Oct. 12, 1971 D. w. SEAR ETAL I 3,611,459

COMPOSITE BOAT Filed Sept. 15, 1969 6 Sheets-Sheet a.

FIGS

Oct. 12, 1971 D. w. SEAR ET A COMPOSITE BOAT 6 Sheets-Sheet 5 Filed Sept. .15, 1969 Oct. 12,1971 D. w. SEAR ETAL 3,611,459

COMPOSITE BOAT Filed Sept. 15, 1969 6 Sheets-Sheet 6 United States Patent 3,611,459 COMPOSITE BOAT Derek W. Sear, Wilslow, Ronald B. Noad, Urmston, and Peter Frank Panter, Didsbury, England, asslgnors to Dunlop Holdings Limited Filed Sept. 15, 1969, Ser. No. 857,855 Claims priority, application Great Britain, Sept. 19, 1968, 43,863/68; Oct. 30, 1968, 51,365/68; Feb. 22, 1969, 9,648/69; June 7, 1969, 28,914/69 Int. Cl. B63b 7/08 US, C]. 9-2 10 Claims ABSTRACT OF THE DISCLOSURE This invention relates to boats incorporating rigid and flexible elements in their construction.

Inflatable boats have the advantage of high impact resistance and stability but tend to be expensive to fabricate and prone to complete loss of buoyancy if punctured, unless expensive baflles are incorporated in the construction. Such inflatable boats possess a further disadvantage in that their hydrodynamic shape is normally worse than a comparable rigid boat and thus they tend to be slower.

One object of the present invention is to provide a boat which possesses the hydrodynamic virtues of a rigid hull together with the buoyancy and tendering ability of an inflatable boat.

According to one aspect of the present invention a composite boat comprises a rigid hull having an inflatable gun- Wale attached to the rim of the hull in such a manner that over a major portion of the length of the gunwale a portion of the gunwale projects outboard of the rim of the hull, and at least the greater part of the gunwale volume lies above the rim of the hull.

According to another aspect of the invention a composite boat comprises a boat of the kind described in the preceding paragraph in which the entire inflatable gunwale is arranged to lie for at least part of its length outboard of the rim of the hull.

According to a further aspect of the invention a composite boat of the kind described in the preceding paragraph comprises a cylindrical inflatable gunwale having a slightly arched shape arranged so that with the boat in an unloaded state the gunwale is for the greater part of its length completely above the rim of the hull considered in side elevation, the gunwale being at its greatest height above the hull rim in the mid-ship region of the hull.

The inflatable gunwales are preferably constructed with flexible air chambers contained within an outer shapeinducing protective covering of rubberised fabric.

The rigid hull may be fabricated from wood, plastic, metal or any other suitable material.

Several embodiments of the invention will now be described with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a composite boat according to the present invention;

FIG. 2 is a perspective view of a portion of an inflatable gunwale showing various constructional details;

'ice

FIGS. 3-6 are transverse cross-sectional views of various ways of attaching the inflatable gunwale to the boat hull;

FIG. 7 is a plan view of a modified boat according to the present invention;

FIG. 8 is a transverse cross-sectional view on the line A-A of FIG. 7;

FIG. 9 is an end view of the stern of the boat shown in FIG. 7;

'FIG. 10 is a side view of a further modified version of the boat shown in FIG. 7;

FIG. 11 is a perspective view of a two-piece composite boat, and

*FIGS. 12 and 13 show two ways in which the two portions of the boat shown in FIG. 11 can be connected together.

A composite boat, as shown in FIG. 1, comprises a rigid hull 1 of V-shaped plan form having conventional side walls 2, base 3 and transome 4 of marine plywood. The pneumatic gunwale 5 is in two cylindrical sections 6 and 7 which converge towards, and are joined together at the prow 8. A spray shield 9 is attached to the gunwale in the prow portion of the boat and supported at its rear edge 10 by a flexible rod (not shown) which is secured at its ends 12, 13 to the gunwale sections 6, 7 and encased in or otherwise attached to a hem 11 formed in the shield fabric.

The pneumatic gunwales each comprises a series of flexible air chambers 14, see FIG. 2, contained within a shape-inducing outer protective covering 15. The outer protective covering of each gunwale section is fabricated, by stitching, from a single piece of nylon fabric coated on the exterior surface only with a chlorosulphonated polyethylene compound. This rubberised fabric is then attached along its two longitudinal edges 16, only one of which is shown in FIG. 2, to the rim of the rigid hull. Each air chamber is provided with a valve 17 which protrudes through a hole 18 in the outer protective covering. This hole, which is provided with a cover 19, acts as a means of entry for the deflated air chamber. At the prow 8 Where the two gunwales are joined, a polyurethane foam filling 20 is used in place of the flexible air chambers.

The inflatable air chambers can also be introduced into the outer protective covering in any of various methods.

Several ways of attaching the gunwale sections to the rim of the hull are described below.

The longitudinal edges 16 of the protective covering 15 can be attached to the rim 21 of the hull by adhesive and reinforced by longitudinal rubberised fabric doublers 22 adhesively attached to the rim and outer protective covering, see FIG. 3.

An alternative way of attaching the covering is to produce the protective cover in a cylindrical form, see FIG. 4, and then attach longitudinal doublers 23 to the cylinder for mechanical or adhesive attachment to the hull rim 21.

A further alternative way of attaching the covering can be by means of an inflatable seal.

The rim 21 of the rigid hull, see FIG. 5, is provided with a dovetail cross-section female channel 24. The outer protective covering of each inflatable gunwale section is provided on its lower surface with a corresponding flexible, inflatable, male locating member 25. Conveniently the male member may be an extruded tube formed from a synthetic elastomer and adhesively attached to the inflatable buoyancy tube. This male member comprises a wider base portion 26 and a narrower hollow convoluted portion 27, see FIG. 6, which is of sufliciently small dimensions to pass between the converging edges 28 of the female channel section. When inflated the male member expands from the convoluted form shown in FIG. 6 to form a water-tight joint with the inner surface of the female member, as shown in FIG. 5.

rIn a modified version of the boat described above, shown in FIGS. 7-9, the assembled pneumatic gunwale 29 is in two cylindrical sections 30, 31 one for each side of the boat. One end 32, 31 of each gunwale section is mechanically secured to one of two specially shaped portions 34, 35 of the transom 36, see FIG. 9. Each specially shaped portion of the transom is arranged to embrace the inboard side of its respective gunwale section along a semi-circular arc of contact and support the gunwale section so that, at the point 34, 35 of mechanical attachment to the transom, the longitudinal axis 37, 38' of each gunwale section is substantially vertically above the widest part of the hull. The gunwale sections are arranged so that their longitudinal axes 37, 38 are parallel to the longitudinal axis 39 of the boat for the rear half of their length and converge towards the prow in the front half.

Thus for parts of their lengths the gunwale sections extend outside and overhang the hull. The gaps formed between the gunwales and the hull are filled by two suitably shaped longitudinal rubberised fabric fillets 41, 42 known as doublers. These doublers, which serve as the means for locating the gunwale sections, are each constructed by placing two suitably shaped pieces of two ply rubberised fabric 43, 44 or other suitable material one on top of the other and sewing the two pieces of fabric together with a longitudinal row of stitches, shown at positions 45 in FIG. 8, arranged to follow a line parallel to the axis of the gunwale to which the doubler is to be fixed. The longitudinal row of stitches is suitably positioned relative to the longitudinal edges of the fabric pieces to allow two adjacent longitudinal edges 46, 47 of the doubler, so formed, to be adhesively secured to the gunwale and the other two edges 48, 4 9 to be adhesively secured one on each side of the rim of the hull.

The arrangement described above has the advantage of giving more space within the boat, since the gunwale sections do not protrude within the hull except to a very limited extent at prow and stern. The flexible attachment of the gunwales to the hull also provides additional shock absorption and reduces the effects of impacts due to slamming or travelling in rough water by allowing the hull to move freely relative to the gunwales.

-In a further modified version, shown in FIG. 10, a composite boat, of otherwise identical construction to that described above, is provided with a cylindrical pneumatc gunwale 50 in two tapering and slightly arched sections 51, 52, one for each side of the boat. The diameter of each gunwale section progressively increases from prow to stern, the arched shape of each gunwale section enabling the midship region 53, 54 of each section to be arranged at a higher level than the prow and stern portions of the section when the gunwale is attached to the boat hull. Attachment of the gunwale sections to the hull is effected by means of a specially shaped transom 55 and fabric fillets 56, 57 exactly as described above.

This arrangement reduces the sag of the gunwale sections in the mid-ship region of the hull thus increasing the forward speed and maneuverability of the boat enabling tight turns to be executed without the risk of submersion of the gunwale on the inside of the turn. The provision of a tapered gunwale section provides the additional buoyancy necessary to counteract the concentration of load of occupants and motor in the stern portion of the boat.

The flexible air chambers employed in the gunwale sections of any of the above embodiments can be fabricated from thin rubber sheet using overlapped seams or from latex using a dipping technique. They can also be manufactured from blow moulded or welded plastics.

[[n order to overcome the problem of transportation and storage any of the boats described above can be constructed in two transversely separated or hinged sections 61, 62, see FIG. 11, each section of the rigid hull terminating along its transverse mating edge in flanges 63, 64. These flanges are connected together by non-corroding nuts and bolts, as shown in FIG. 11, or by a syste of mechanical clamps or clips, two examples of which are shown in FIGS. 12 and 13. FIG. 12 shows a system in which a spring clip 65 engages two correspondingly transversely extending grooves 66 and 67 formed one in each flange 63, 64. The clip 65 may extend continuously across the boat for the total length of the grooves 66 and 67 or may be in several spaced sections only engaging part of the total length of the grooves. FIG. 13 shows a pair of interengaging resilient wire clips 68, 69 in which the head 70 of clip 68 must be depressed to disengage the loop 71 in clip 69 before the boat sections can be parted. Several pairs of interengaging clips are normally employed at spaced locations along the mating flanges of the hull sections to be joined. In all the above arrangements adequate provision must be made to accommodate the inflatable gunwale sections when the rigid hull sections are disengaged or folded.

While in the boats described above conventional hulls with well defined side walls are employed, other dished or angled hull structures may also be employed within the scope of the present invention.

The kind of boat disclosed above can readily be fitted with an outboard motor and possesses the following prop erties. In straight or gently curving motion the gunwale sections do not contact the water, they merely provide a spray deflector and very efiicient fender. When cornering, however, the inside gunwale section becomes partially immersed. This then enables a tight turn to be executed without swamping or excessive heel, since the partially immersed gunwale produces an upward buoyancy force and at all times tends to ride on the surface of the water. The boat therefore has the hydrodynamic advantage of possessing a rigid hull combined with the buoyancy and fendering ability of an inflatable craft.

While the invention has been particularly described with reference to boats of V-shaped plan form incorporating inflatable gunwales comprising flexible air chambers within an outer shape-inducing protective covering it is not limited to such constructions and in its broadest aspect should be construed as including boats of a more conventional archshaped plan form as well as boat s incorporating tubeless inflatable gunwales.

Having now described our invention, what we claim is;

1. A composite boat comprising:

a rigid keel member extending along substantially the length of the hull;

two rigid base members rigidly mounted on and extending from either side of the said keel member to outline the lower hull shape;

rigid side members extending upwardly from the outer edges of the said rigid base members;

a rigid transom member extending upwardly from the rear edge of the said base members; and

a cylindrical inflatable gunwale attached to the upper rim of the upwardly extending side members and having a slightly arched shape arranged so that with the boat in an unloaded state the gunwale is for the greater part of its length completely above the rim of the hull considered in side elevation, the gunwale being at its greatest height above the rim in the midship region of the hull;

said boat being so constructed and arranged that the rigid members form a rigid displacement hull for supporting the boat in conventional manner and that over a major portion of the length of the gunwale member a portion of the gunwale member projects outboard of the upper rim of the hull side members and at least the greater part of the gunwale volume lies above the said upper rim of the hull side members.

2. A composite boat according to claim 1 including an outer protective covering over said gunwale attached along its longitudinal edges to the rim of the hull and reinforced by longitudinal doublers adhesively attached to the rim and outer protective covering respectively.

3. A composite boat according to claim 1 including an outer protective covering over said gunwale in cylindrical form and the covering is attached to the rim of the hull by longitudinal doublers attached to the cover and to the rim of the hull respectively.

4. A composite boat according to claim 1 wherein the gaps formed between the gunwales and the hull are filled by longitudinal doublers which also serve to locate the gunwale sections.

5. A composite boat according to claim 1 wherein the bow portion of the gunwales is filled with solid buoyant material.

6. A composite boat according to claim 1 wherein the rigid hull has a V-shaped plan form.

7. A composite boat according to claim 1 wherein the inflatable gunwale is secured to shaped portions of the transom arranged to embrace the inboard side of each gunwale section.

'8. A composite boat according to claim 1 wherein the hull is arranged to be divisible into at least two separate or hinged sections, the mating edges of each section being provided with corresponding flanges arranged to be detachably connected together.

9. A composite boat according to claim 1 wherein a doubler for securing the gunwale to the rim of the hull comprises two layers of suitably shaped material one on top of the other and sewn together by a longitudinal row of stitches arranged to follow a line parallel to the axis of the portion of the gunwale to which the doubler is to be fixed, the longitudinal row of stitches being suitably positioned relative to the longitudinal edges of the doubler so that two of the adjacent edges of the doubler can be secured one on each side of the rim of the hull.

10. A composite boat according to claim 1 comprising an outer protective covering of nylon fabric coated on its exterior surface with a chlorosulphonated polyethylene compound.

References Cited UNITED STATES PATENTS 2,794,992 6/1957 Metzing 92 2,531,549 11/1950 Boyd 92 FOREIGN PATENTS 677,643 1/ 1964 Canada 92 1,431,128 1/1966 France 911 MILTON BUCHLER, Primary Examiner C. A. RUTLEDGE, Assistant Examiner 

